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Tu, Ronghui. "Semi-fragile digital audio watermarking." Thesis, University of Ottawa (Canada), 2003. http://hdl.handle.net/10393/26432.
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The digital information has brought many changes to our life in recent decades. With the rapid growth of digital information, a lot of new techniques are coming into being. Digital watermarking is one of them. This thesis presents a semi-fragile audio watermarking scheme which can be applied to content authentication or copyright verification. The major contribution of this thesis is the introduction and implementation of a unified copyright verification and content authentication algorithm for audio signal.
In our approach, we embed the watermark in the discrete wavelet domain of an audio by using quantization technique. The discrete wavelet domain has both the spatial and frequency information which make it possible to detect various modifications. The advantage of using quantization technique is that we could extract the watermark without using original audio.
In the procedure of watermark extraction, some signal processing operations may change the length of testing audio. We employ a matching filter to locate the start point of the watermark. This filter can be generated during the embedding procedure. The cost of the filter is very small.
We conduct several experiments for evaluating the performance of this new watermarking technique on both of two applications---content authentication and copyright verification. Our experimental results show that this scheme is robust to mp3 compression, additive noise, and filtering attacks. At the same time, the embedded watermark can also be used to check whether the audio content has been modified or not. If the audio is determined to be modified, an assistant program can be invoked to find out where the modification is.
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Cvejic, N. (Nedeljko). "Algorithms for audio watermarking and steganography." Doctoral thesis, University of Oulu, 2004. http://urn.fi/urn:isbn:9514273842.
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Broadband communication networks and multimedia data available in a digital format opened many challenges and opportunities for innovation. Versatile and simple-to-use software and decreasing prices of digital devices have made it possible for consumers from all around the world to create and exchange multimedia data. Broadband Internet connections and near error-free transmission of data facilitate people to distribute large multimedia files and make identical digital copies of them. A perfect reproduction in digital domain have promoted the protection of intellectual ownership and the prevention of unauthorized tampering of multimedia data to become an important technological and research issue.
Digital watermarking has been proposed as a new, alternative method to enforce intellectual
property rights and protect digital media from tampering. Digital watermarking is defined as imperceptible, robust and secure communication of data related to the host signal, which includes embedding into and extraction from the host signal. The main challenge in digital audio watermarking and steganography is that if the perceptual transparency parameter is fixed, the design of a watermark system cannot obtain high robustness
and a high watermark data rate at the same time. In this thesis, we address three research problems on audio watermarking: First, what is the highest watermark bit rate obtainable, under the perceptual transparency constraint, and how to approach the limit? Second, how can the detection performance of a watermarking system be improved using algorithms based on communications models for that system? Third, how can overall robustness to attacks to a watermark system be increased using attack characterization at the embedding side? An approach that combined theoretical consideration and experimental validation, including digital signal processing, psychoacoustic modeling and communications theory, is used in developing algorithms for audio watermarking and steganography.
The main results of this study are the development of novel audio watermarking algorithms, with the state-of-the-art performance and an acceptable increase in computational complexity. The algorithms' performance is validated in the presence of the standard watermarking attacks. The main technical solutions include algorithms for embedding high data rate watermarks into the host audio signal, using channel models derived from communications theory for watermark transmission and the detection and modeling of attacks using attack characterization procedure. The thesis also includes a thorough review of the state-of-the-art literature in the digital audio watermarking.
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Costantini, Giacomo. "Localizzazione audio mediante tecniche di watermarking." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/5847/.
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Tegendal, Lukas. "Watermarking in Audio using Deep Learning." Thesis, Linköpings universitet, Datorseende, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-159191.
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Watermarking is a technique used to used to mark the ownership in media such as audio or images by embedding a watermark, e.g. copyrights information, into the media. A good watermarking method should perform this embedding without affecting the quality of the media. Recent methods for watermarking in images uses deep learning to embed and extract the watermark in the images. In this thesis, we investigate watermarking in the hearable frequencies of audio using deep learning. More specifically, we try to create a watermarking method for audio that is robust to noise in the carrier, and that allows for the extraction of the embedded watermark from the audio after being played over-the-air. The proposed method consists of two deep convolutional neural network trained end-to-end on music with simulated noise. Experiments show that the proposed method successfully creates watermarks robust to simulated noise with moderate quality reductions, but it is not robust to the real world noise introduced after playing and recording the audio over-the-air.
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Bounkong, Stephane. "Digital image watermarking." Thesis, Aston University, 2004. http://publications.aston.ac.uk/13264/.
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In recent years, interest in digital watermarking has grown significantly. Indeed, the use of digital watermarking techniques is seen as a promising mean to protect intellectual property rights of digital data and to ensure the authentication of digital data. Thus, a significant research effort has been devoted to the study of practical watermarking systems, in particular for digital images. In this thesis, a practical and principled approach to the problem is adopted. Several aspects of practical watermarking schemes are investigated. First, a power constaint formulation of the problem is presented. Then, a new analysis of quantisation effects on the information rate of digital watermarking scheme is proposed and compared to other approaches suggested in the literature. Subsequently, a new information embedding technique, based on quantisation, is put forward and its performance evaluated. Finally, the influence of image data representation on the performance of practical scheme is studied along with a new representation based on independent component analysis.
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Kardamis, Joseph R. "Audio watermarking techniques using singular value decomposition /." Online version of thesis, 2007. http://hdl.handle.net/1850/4493.
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Wang, Yulin. "Image and video watermarking." Thesis, Queen Mary, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416655.
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Chen, Bingwei. "Adaptive watermarking algorithms for MP3 compressed audio signals." Thesis, University of Ottawa (Canada), 2008. http://hdl.handle.net/10393/27963.
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MPEG-1 Layer 3, known as MP3, has generated a significant popularity for distributing digital music over the Internet. MP3 compresses digital music with high ratio while keeping high sound quality. However, copyright issue is raised because of illegal copy, redistribution and various malicious attacks.
Digital watermarking is a technology that allows users to embed some imperceptible data into digital contents such as image, movie and audio data. Once a watermark is embedded into the original MP3 signal, it can be used to identify the copyright holder in order to prevent illegal copy and to verify the modification from the original content.
This thesis presents two novel adaptive watermarking algorithms for MP3 compressed audio signals for copyright protection. Based on Human Auditory System, the proposed algorithms calculate the energy of the original audio signal and apply Gaussian analysis on MP3 frames to adaptively adjust the watermarking coefficients. Watermark is embedded adaptively and transparently during the MP3 compression. The first watermarking algorithm detects watermark based on Gaussian distribution analysis. To enhance the security of the watermark, the second watermarking algorithm embeds random watermark pattern and uses correlation coefficient to detect watermark. Both algorithms support blind watermark detection and perform well. The first algorithm is more robust while the second algorithm is more secure.
LAME 3.96.2 open source was used as standard ISO MP3 encoder and decoder reference in this study. The experimental results show that the proposed watermarking algorithms can work on a variety of audio signals and survive most common signal manipulation and malicious attacks. As expected, the watermarking algorithms provide superior performance on MP3 compression.
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Zheng, Dong. "RST invariant digital image watermarking." Thesis, University of Ottawa (Canada), 2003. http://hdl.handle.net/10393/26554.
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Digital image watermarking has been proposed as a method to ensure the copyright protection and credibility of images by means of embedding a known piece of digital data into host images. To be useful, a good watermarking scheme should be robust against all known attacks to a certain degree based on requirements.
In this thesis, we propose a novel digital image watermarking scheme that is invariant to rotation, scaling, and translation (RST). We embed watermark in the log-polar mapping (LPM) of the Fourier magnitude spectrum of original image, and use the phase correlation between the LPM of the original image and the LPM of the watermarked image to calculate the displacement of the watermark positions in LPM domain. The exhaustive search method is used to retrieve the watermark if the original image is unavailable.
Spread spectrum technique and perceptual model are used to enhance the security and to achieve the optimum balance between invisibility and robustness. Stochastic analysis is used to determine the optimum threshold to minimize the total false probability of detection. In this thesis, we discuss all these in detail and show how they work with the main watermarking scheme to give better results.
We implement this watermarking algorithm to analyze its performance. The evaluations demonstrate that the scheme is invariant to rotation and translation, invariant to scaling when the scale is in a reasonable range, and very robust to JPEG compression and other attacks.
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Ghosh, Debeshi D. "Audio Watermarking Using DWT Algorithm and Symmetric Key Cryptography." Thesis, California State University, Long Beach, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10263604.
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<p> Watermarking is the process of embedding information into a carrier signal such as audio, video, and images. It is widely used to protect proprietary information in the signal to prevent information theft or duplicity. In this project, an audio watermarking system with dual layer security has been implemented. The entire system is divided into two sections that are independent, but have been combined, to make a unique system that provides increased levels of robustness. The first part of the project involves encrypting an embedded image (watermark) using the XOR method of symmetric key cryptography. Encryption is then followed by watermarking. The digital wavelet transform (DWT) algorithm was used to embed the encrypted image into an audio signal. This ensures that even if this image is removed during an attack to the carrier signal, it cannot be interpreted or used. Though encryption combined with watermarking is unconventional, it proves to be an effective technique when implemented correctly.</p>
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Guo, Huiping. "Digital image watermarking for ownership verification." Thesis, University of Ottawa (Canada), 2003. http://hdl.handle.net/10393/29018.
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The development of the Internet has greatly contributed to the expanded use of digital media, for example, images, audio, video, VRML objects. These media can be duplicated unlimitedly without any quality loss and can also be easily distributed and tempered. This presents problems of digital media security, such as copyright protection and authentication, which creates a pressing need for digital media protection schemes. A new emerging technology, digital watermarking, protects digital media by embedding a robust signal directly into the media, thus providing a promising way to protect the digital media from illicit copying and manipulation.
In this thesis, we mainly consider digital image watermarking for ownership verification. Though lots of such schemes have been proposed in literature, there are still some problems that have not been addressed or have not been adequately addressed such as how to detect a watermark progressively while at the same time be robust to geometrical transformations, how to embed a watermark in the fractal domain and how to embed a watermark into an object in an image instead of into the whole image. Several new watermarking algorithms are proposed here to address these problems respectively and experiments show satisfactory results.
The next problem that has been ignored by the watermarking community is the joint ownership verification. If an image is created collaboratively by multiple owners, all current watermarking schemes will fail to protect the image from potential dishonest owners, since they are only designed to protect an image from dishonest users. To address this problem, a novel framework of the watermarking system that makes use of a secret sharing scheme is proposed. Based on this framework, several new watermarking algorithms are proposed where the secret watermark embedding key is split into shares and each owner holds one share. Multiple watermarks contributed by each owner are embedded into spectrum domain of the image and multiple thresholds are set so that the watermark can verify joint ownership as well as partial ownership. To the best knowledge of the author, the problem of joint ownership has not been addressed so far and the watermarking schemes proposed are the first ones to address them.
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Ahmaderaghi, Baharak. "Image watermarking based on Shearlet transform." Thesis, Queen's University Belfast, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.703885.
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This thesis is dedicated to investigating image watermarking techniques based on the recently proposed transform called 'Shearlet' as the watermark embedding domain. The aim is to obtain new levels of imperceptibility and robustness which lead to higher data hiding capacity. With this idea in mind, new image watermarking algorithms in the Discrete Shearlet Transform domain are developed. First, combined with state of the art spread spectrum embedding methodology, a new watermarking algorithm using DST is designed in order to obtain better performance. The system was tested using five common types of image attacks. The results indicated that a combination of DST and spread spectrum embedding was more rQbust and more imperceptible compared with two well-known watermarking systems based on OCT and DWT domain, using the same embedding strategy. Second, a new perceptual image watermarking scheme using discrete Shearlet transform was developed by adapting a spatial visual model to the structure of the DST decompositions. The system performance was compared, under the same condition using the same embedding and extracting strategy with two watermarking systems based on DWT and DTCWT domain. Experimental results show the proposed method's efficiency by having higher imperceptibility and capacity and, at the same time, being more robust against some of the attacks. Finally, a Shearlet transform-based watermarking framework is proposed for blind watermarking, improving the other transformed-based methods. In order to develop this blind watermarking system, statistical modelling was applied to describe the behaviour of discrete Shearlet transform coefficients based on different sub-bands and resolutions. In order to investigate system performance, the obtained results are compared with watermarking systems based on DWT using the same embedding strategy. The overall results indicate the improvements in performance in order to assess the claims made during this research about the usage of the Discrete Shearlet Transform as a new embedding domain.
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Wong, Hon Wah. "Image watermarking and data hiding techniques /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20WONGH.
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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003.<br>Includes bibliographical references (leaves 163-178). Also available in electronic version. Access restricted to campus users.
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Jiang, Jing Jing. "Self-synchronization and LUT based client side digital audio watermarking." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2550676.
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Yuan, Xiao Chen. "Robust and geometric invariant digital image watermarking." Thesis, University of Macau, 2010. http://umaclib3.umac.mo/record=b2182875.
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Earl, John William. "Image and video watermarking with overcomplete transforms." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613316.
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Hsu, Yu-Feng, and 許宇鳳. "Digital Image and Audio Watermarking." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/25753520993393753461.
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碩士<br>國立臺灣大學<br>電信工程學研究所<br>89<br>The world has evolved into a multimedia age with booming internet connectivity, which enables us to carry and distribute digital data without any difficulty. However, this convenience also facilitates illegal uses of copyrighted data. To prevent pirating and deal with the intellectual property problem, the watermarking techniques are researched and developed to provide the author and owner with another method to declare their ownership.
Two watermarking schemes on color images and digital audio data are proposed in this thesis. For color image watermarking, the watermark is inserted into the index domain of a palette-based image. For audio watermarking, we will embed audio clips into host audio as watermarks other than the commonly used binary sequences in a spread spectrum manner. In both methods, the watermark is embedded repeatedly but the repeating process has different influences on the two forms of media.
This thesis consists of six chapters. A general introduction to digital watermarking is made in chapter 1. In chapter 2, the concept of watermarking will be explained, classifications of watermarks will be given, and related works in digital image watermarking will be summarized. The proposed image watermarking technique on palette-based color images using neural network training will be presented in chapter 3. After that, related works in audio watermarking will be introduced in chapter 4. In chapter 5, the concept of sequences of autocorrelation function with zero sidelobe will be explained, our audio watermarking scheme based on the spread spectrum concept will be presented, and experimental results using a new quantitative approach will be displayed. Finally, a concluding remark and future research directions shall be given in chapter 6.
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Chung, Mu-San, and 鍾木三. "Digital Watermarking Methods for Image and Audio Signals." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/46622868004934555937.
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碩士<br>國立中山大學<br>資訊工程學系研究所<br>89<br>Encryption, digital signature and digital watermark are three popular methods to prevent a wide variety of multimedia products from illegal copy or subterfuge attacks. In particular, digital watermarking recently draws a lot of attention since it hides desirable information in transmitted audio, image and video data files without affecting much the data quality. The thesis proposes two watermarking methods for audio and image data. And both watermarking methods embed watermark signals in the spatial/time domain using a so-call Pixel Weight Table. The experiment results shows that the two methods have good performance. In addition, I propose a guantitive measuring method, called APSNR, to characterize the audio perceptual transparency.
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Tai, Yuan-Hsiang, and 戴元翔. "Digital Audio Watermarking Techniques." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/88982778400158946239.
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Ya-Wen, Lu, and 呂雅文. "Digital Audio Watermarking and." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/64529496671049267594.
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碩士<br>國立臺灣大學<br>電信工程學研究所<br>91<br>Abstract
In the last few years, the world has evolved into a multimedia age with booming Internet connectivity. It has become very easy to obtain and download digital data. However, easy access and duplication have posed serious problem of piracy in media distribution. The watermarking techniques are researched and developed to protect the ownership of owner and the author. In addition, the amount of bandwidth for multimedia applications and the dimensions of digital have been continuously growing, so that retrieval of information is becoming the new emergency. A content-based audio retrieval system is researched to propose a convenient and intuition search engine.
Two watermarking schemes on digital audio data are proposed in this thesis. We will embed binary sequence into host audio as watermarks in both schemes. One of them can embed multiple information by using the Hadamard matrix and the random sequence. The other improves the convention echo hiding method by using a time-spreading kernel. In both methods, the watermark is embedded repeatedly and host signal does not need in the extraction procedure.
In audio retrieval system, the melody of query is used as the feature. The pitch sequence is extracted using the autocorrelation function and smoothed in post-processing step. DTW and key-shifting method are used to compute the warping distance between the input pitch sequence and that of each sing in the database. In this system, a user can specifies a query from anywhere in the middle of a song and the top 2 success rate is over 70%, based on a database of 36 songs and a dataset of about 100 test clips.
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Cheng, Ji-Shiung, and 鄭吉雄. "Intelligent Watermarking for Audio Signals." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/78286929601877467622.
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碩士<br>國立中正大學<br>資訊工程研究所<br>88<br>In this thesis, we propose a new intelligent digital watermarking technique for audio signals based on neural networks that are employed to memorize the relationships between the original audio signals and watermarked audio signals. Due to those neural networks posses the memorization and generalization capabilities, our approach is capable of extracting watermarks without original audio signals. Moreover, our watermarking method makes the watermark imperceptible by using the frequency-masking characteristics of the human auditory system (HAS). Furthermore, a pair of watermarks (a signal-dependant watermark and an owner’s signature) is embedded into the audio signals so as to achieve the content protection and authentication. Finally, extensive experimental results are exhibited to illustrate the performance of our watermarking technique can be improved.
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Chang, Li-Chun, and 張立鈞. "Digital watermarking of audio signals." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/88684654504954397665.
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碩士<br>國立中正大學<br>電機工程研究所<br>88<br>Past few years multimedia have chance to advance, especially in MPEG-1 Layer 3 (MP3)─a standard of new generation in audio compression. Its compression rate is 1：10 ~1：12. This rate might economize a lot of saving spaces and might be more convenient for spreading on Internet. Therefore, the widespread of MP3 let people can search from Internet easily. But, at the same time, this kind of convenience let illegal people or pirate, through digital media or Internet, copy the original works without paying. These problems need to resolve urgently, so to develop the technology putting owner copyright on electronic multimedia is so-called the technology of digital watermark. High efficiency of watermarking technology can become a kind of authentication. Through watermarking, the original signet, signature, or special data pattern can be hidden in digital work； at the same time; it will not cause the damage of the quality of works and will not be noticed by users. Such kind of watermark also can withstand certain degree of destruction while copying.
The purpose of this thesis is by the multimedia audio information to do the research in technology of digital watermark and probe into the technology of compression in MPEG-1 Layer3 (MP3). Cooperating the characteristic of audio and using the energetic variation for three next sections to seek for the new appropriate method. The action of embedding digital watermark will not affect the quality of audio. Furthermore, this embedding will not only provides enough robustness for digital watermark to bear several kinds of attacks, including MP3 compression, low-pass filter, normalization, D/A converter, and clipped signal but also can keep the completeness of digital watermark. When authenticating the audio information, we use digital watermark to detect audio information or extracting the information out of digital watermark quickly without original audio signal. Additionally, we use error correct code and concept of synchronization code in digital watermarking method to enhance the reconstruction rate materially, when the watermark was attacked.
In the experimental testing, the watermarked audio signal is listened by seven testers and all of then feel satisfactorily. 70 percent of testers can’t notice difference between the original and watermarked signal. At the quality, the extracting rate of watermark is 98 percent after above-mentioned kinds of attacks. Thus, we prove that our digital watermark method is useful and applied.
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Tsai, Cheng-Fu, and 蔡正富. "A DWT-Based Digital Audio Watermarking." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/72166077143270442932.
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碩士<br>國立東華大學<br>資訊工程學系<br>92<br>In audio signals, with the widespread use of Internet and proliferation of digital audio distribution in MP3 form make the copyright protection of digital audio works more and more important. In this thesis, a DWT-based digital audio watermarking is proposed. With the Discrete Wavelet Transform（DWT）, the audio signal can be transformed into frequency domain ranging from low frequency to high frequency. Besides, the high frequency spectrum is less sensitive to human ear. That is the reason why the high frequency component is usually discarded in the compression process. Therefore, information to be hidden can be embedded into the low frequency component to against the compression attack.
In our experiments, the logo of National Dong Hwa University (NDHU) is embedded into an audio signal. The performance of the proposed technique is evaluated by the normalized correlation between the original logo and the extracted one. Experiment results show that the proposed algorithm is robust to the compression and noise attacks.
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郭俊榮. "Audio Watermarking Systems using Auditory Masking." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/57808027958338770332.
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碩士<br>國立臺北科技大學<br>電機工程系碩士班<br>92<br>With rapid development of digital signal processing and the Internet communication, digital audio in market is apt to be illegally transported and duplicated by people. Two audio watermarking schemes that make use of human auditory masking and spread spectrum communication are investigated for the purpose of ownership declaration of intellectual property. One scheme employs the direct sequence spread spectrum and phase spectrum coding (DSSS/PSC), and the other applies the direct sequence spread spectrum and binary phase-shifting keying (DSSS/BPSK) to embed digital watermark into cover audio without sacrificing the perceptual quality. The former is by changing the phase and the latter adjusts the magnitude of the frequency spectrum that is below the auditory masking threshold of the cover audio. The experimental results show that the extracted correct rates are at least 99.64 % for both DSSS/PSC and DSSS/BPSK schemes. When suffering an attack, e.g. MP3 compression, resampling, and filtering, etc, the performance of DSSS/BPSK is shown to be more robust than that of DSSS/PSC. On the contrary, the DSSS/PSC scheme is proved to be a good fragile watermarking for protecting the cover audio.
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Lai, Jun-Jie, and 賴俊傑. "Image Watermarking Techniques." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/28798691354516442293.
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碩士<br>世新大學<br>資訊管理學系<br>90<br>The prevailing usage of networks and the huge amount of multimedia data have incurred hot issues on copyright protection. Digital watermarking techniques have high potential in providing an efficient way to solve this problem.
This thesis proposed four image watermarking methods. One of them embed watermark in the spatial domain, two of them work in the DCT frequency domain, and the other one copy with the Wavelet frequency domain. Observing the experimental results, all of our proposed methods satisfy the requirement of imperceptibility and robustness.
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Tang, Jiun-Lin, and 湯浚霖. "A Study of Combined Watermarking and Audio Fingerprinting for Audio Authentication." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/a5zths.
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碩士<br>國立臺中科技大學<br>資訊工程系碩士班<br>100<br>The digital audio is easily tampered with during the process of transmission. However, authenticating the identity of the sender or even detecting tamper is difficult. Therefore, in this thesis the watermarking and audio fingerprinting techniques are combined to solve these issues. The scheme is in four parts. The first part involves the audio masking effect where the watermark is embedded in the audio’s frequency domain after Discrete Wavelet Transform. The second part takes the audio signal containing the watermark and parses it through for feature acquisition by Mel-Frequency Cepstral Coefficient (MFCC) and Line Spectral Pairs (LSP) in order to construct the audio fingerprint. The third part involves the watermark extraction from the audio carrier. The fourth and final part is the verification and comparison stage. The fours variables for verification and comparison are the respective Normalization Coefficient (NC), Peak Signal to Noise Ratio (PSNR), audio fingerprint PSNR, and the difference between Audio Watermark Fingerprint (AWF) and No Audio Watermark Fingerprint (NAWF). Experimental results show that the embedded watermark is not detectable by the human ear. Furthermore, the scheme is robust against some common audio attacks, like, low pass filtering, cutting, noise adding, MP3 loss compression and amplitude amplification. After any of these attacks, the audio signal watermarking retrieval does not require the original audio signal. Also, the NC value showed a robustness of more than 90%. The combined watermark and fingerprint allows the detection of tampering. Furthermore, the difference value between audio fingerprint AWF and NAWF can reveal the location of the tampered audio signal.
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Ho, Yi-Lun, and 何宜倫. "Audio Watermarking Based on Harmonic Amplitude Modification." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/71451895319886542917.
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碩士<br>國立清華大學<br>電機工程學系<br>90<br>Digital watermarking is regarded as an effective method for copyright protection of digital multimedia files. This paper proposed a new algorithm that hides the binary information in audio signal by modifying magnitudes of harmonic components. The harmonic components are significant in the auditory perception and are supposed to be more robust than the masked area, which is utilized in conventional audio watermarking techniques. Relative algorithms are also developed to make it possible to process a complete audio data automatically. The experiment results confirm that the watermark has a recovery accuracy above 90% after the watermarked data is attacked by most commonly used signal processing, such as digital-analog conversion, low-pass filtering, and lossy compression.
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Wu, Feng Chuan, and 吳豐全. "Improvement of Data Capacity for Audio Watermarking." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/bwdf9x.
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碩士<br>國立臺北科技大學<br>電子工程系研究所<br>104<br>Owing to the quick development of computer and internet, audio watermarking has become a popular technique in recent years. Audio watermarking embeds a series of copyright images into the digital audio signal to protect intellectual property rights. However, audio watermarking should have some important properties, such as perceptual transparency, robustness, and security, for satisfying the demand of practical applications. Recently, most of audio watermarking technique researches focuses on perceptual transparency and robustness only few researches focus on capacity and security. Therefore, the aim of our research is to improve audio watermarking efficiency and data capacity.
This thesis proposes two methods to improve audio watermarking capacity. In method 1, we use chaotic encryption and Cartesian-polar coordinate transform and combining discrete wavelet transform (DWT) with singular value decomposition (SVD). In method 2, we use run length encoding (RLE) and chaotic encryption combining DWT with discrete cosine transform (DCT) and SVD. Experimental results show that proposed methods not only can provide effective capacity and security, but also have robustness and perceptual transparency.
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曾嘉波. "Digital Audio Watermarking Based on Linear Prediction." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/32475604235081248548.
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碩士<br>國立高雄第一科技大學<br>電腦與通訊工程系<br>89<br>The amount of usage of the internet grow quickly, and audio compression technique attains to maturity. The prospect of on-line music is predictable. However, the digitalized data allows data duplicating without loss of fidelity. This makes intelligent property protection becomes more important. In order to protect the data from illegal copying, we can use cryptographic techniques. The cryptosystem restricts the access of data, so we must develop other methods to supplement the weakness of cryptographic techniques. Digital watermarking can meet this demand and becomes an active research topic in the signal processing community.
In the thesis, a new digital audio watermarking technique is proposed. In the embedding scheme, four steps involved are as follow. First, use linear prediction analysis to find the feature parameters that represent the audio spectrum. Second, a vector quantization algorithm is applied to quantize feature parameters. Third, modify the codebook index number to embed watermark. Fourth, use the quantized parameters to synthesize audio signal. In extracting scheme, three steps are given below. First, pass the watermarked audio through the same linear prediction analysis to find feature parameters. Second, find the optimal index number in the codebook by matching feature parameters with codebook parameters. Third, the watermark can be extracted from odd- even property of index number.
The experiments show that the proposed audio watermarking scheme have very good sound’s quality, and can resist the MPEG-1 layer 3 audio compression attack.
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Ko, Bo-Hur, and 柯柏合. "Discrete Wavelet Transform Based Audio Watermarking Development." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/66346272502898635565.
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碩士<br>國立暨南國際大學<br>電機工程學系<br>95<br>In this paper, we proposed a novel audio watermarking technique that the information is embedded into wavelet coefficients by modifying the amplitudes of entropy. The robust audio watermarking algorithm that utilizes the low frequency coefficients in DWT (discrete wavelet transform) as its guide to locate is proposed. The amount of modification to the amplitude is determined by the amount of distortion detected by the human ear. Unlike traditional usage, entropy plays the main role in the proposed watermarking technique. The performance of the proposed scheme in terms of SNR(signal to noise ratio) is analyzed. A relation between the number of consecutive coefficients and the SNR is presented. The experimental results show that the embedded data are robust against most common signal processing and attacks, such as MP3 compression, Gaussian noise, re-sampling, chopping and filtering.
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Yang, Wen-Lung, and 楊文隆. "Image Watermarking Using Wavelets." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/59825955003464448782.
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碩士<br>南台科技大學<br>電子工程系<br>92<br>With the rapid development of Internet, intrusions of copyrights are getting more and more serious. Digital products such as pictures, MP3 music or VCD are spread, copied or modified without the author’s permission, which results in the so-called “Intrusion of Intellectual Property Rights (IPR).” Some scholars proposed solutions such as digital watermark, digital fingerprints, or digital signatures to the problem. With the insertion of the author’s digital portrait, fingerprint, trademark, or picture into the priced media, these inserted data become the basis of copyright certification. From then on, digital watermark is widely used.
In this thesis, we proposed a new digital watermarking technique based on discrete wavelet transformation. The proper wavelet band for inserting the watermark was found by analyzing the attacks of JPEG compression, blurring, sharpening, and histogram equalization on the original picture. Then we insert the watermark followed the binary difference relation matrix (BDRM) which was derived by analyzing the wavelet coefficients’ variation of the original and histogram equalized pictures. The BDRM doesn’t only have less data for replacing the original picture but also promote the accuracy of watermark extracting. Besides, in order to ensure that the watermark can resist the attack of cutting, we adopt the technique of toral automorphisms, dislocating watermarks randomly and inserting them to the middle frequency portion of original picture.
Experiment results show that the proposed technique of watermarks is able to resist attacks such as JPEG compression, blurring, sharpening, sharpening as well as blurring, and cutting.
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Huang, Ching-Ya, and 黃靖雅. "RST-invariant image watermarking." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/t2pjs5.
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碩士<br>國立臺灣師範大學<br>資訊工程研究所<br>97<br>Traditional watermarking schemes are sensitive to geometric distortions, in which synchronization for recovering the embedded information is challenging due to the disorder caused from rotation, scaling or translation (RST). This thesis presents robust watermarking algorithms based on SIFT features, which are resilient to geometric attacks, including RST, and even warping. By embedding watermark bits in RST-invariant keypoints in the image and aligning the embedding direction according to the principle axis, watermark can be well preserved and extracted even if the image is destroyed by RST. Since limited robust features can be found in the spatial domain, deriving a robust spatial-domain watermarking is another difficult problem. However, besides the frequency-domain watermarking schemes, we also design a quantization watermarking scheme in the spatial domain, which is robust to RST. Experiment results show the proposed algorithms are superior to many existing works.
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周雙安. "Study on Echo Hiding Techniques for Audio Watermarking." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/61256528079580886398.
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Lee, Wei-Cheng, and 李維晟. "Detection and Decoding of Audio Spread-Spectrum Watermarking." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/tp6qxt.
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碩士<br>國立交通大學<br>電信工程系所<br>92<br>In this thesis, we address the problem of the performance analysis of audio watermarking systems that use a spread spectrum technique in the discrete cosine transform (DCT) domain. Two tests are involved in the ownership verification process. First, a watermark detector decides whether the audio under test contains a watermark generated with a certain key. If the audio is watermarked , then authorship by the key holder is proved and extraction of hidden message can be performed by a detector. Most current research concentrate on correlation detectors, despite evidence showing that the underlying Gaussian model assumption does not match the intrinsic natures of DCT coefficients. Recognizing this, we first investigate a statistical approach that uses the generalized Gaussian probability to characterize the DCT coefficients and then use it as a basis for the application of statistical decision theory to the design of efficient detector and decoder structures. We also generalize this approach to the possible nonexistence of a statistical description of the original audio.
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Liu, Chi-sheng, and 劉啟昇. "Digital Audio Watermarking Utilizing Discrete Wavelet Packet Transform." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/55g4th.
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碩士<br>朝陽科技大學<br>網路與通訊研究所<br>92<br>The past few years have seen an explosion in the use of digital media. Editing the content of digital signals is easy, safe and economical. Thus, the rights of the author are endangered. The digital watermarking technique tries to solve the ownership problems and protect the copyright of the owner. In digital audio watermarking, the goal is to embed some meaningful message information in the original audio signal without perceptional distortion. Up to now, audio watermarking technique in frequency domain mostly takes advantage of Short Time Fourier Transform (STFT) to analyze the auditory masking effect. The STFT estimates spectrum in fixed window length during the whole audio signal. Furthermore, using longer window length obtains more complete frequency resolution certainly than fixed length, but leads to incomplete time resolution. In addition to the masking effect, there are many nonlinear properties in Human Auditory System (HAS). For instance, the resolution of low frequency in ear is more sensitive than high frequency. Therefore, the time-frequency resolutions are constant that can not react to the nonlinear properties. In this paper, we propose Discrete Wavelet Packet Transform (DWPT) to analyze masking effect efficiently. The idea is to employ dynamic and adaptive window length of analysis with the entire audio signal. Thus, the DWPT can not only improve on analysis of the nonstationary audio signal but also fit the frequency resolutions for the nonlinear properties in HAS. After embedding, the watermarked signal is robust enough to common audio processing such as cropping, shifting and MPEG audio compression. In the detection/extraction phase, the characteristic of autocorrelation function like the impulse function is employed to detect the watermark signal is existed or not. If it is, then the meaningful message can be extracted correctly from the watermarked signal without the original signal.
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Huang, Chao-Cyun, and 黃超群. "A hybrid audio watermarking technique in cepstrum domain." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/04970192319920609086.
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碩士<br>國立東華大學<br>資訊工程學系<br>97<br>Along with the progress relating to computer hardware and software, the Internet has become the most popular medium for transmitting various forms of digital multimedia. Since the environment of the Internet is open and free browsed, the protection of digital information transmitted on the network has become an important research topic in recent years. Watermarking techniques, therefore, have received much attention. Embedding digital watermark in digital media is an important method for the protection of intellectual property right.
In this thesis, we propose a hybrid watermarking technique that makes use of combining two techniques to embed a binary image into an audio data in the cepstrum domain. Moreover, we apply the MPEG-1 psycho-acoustic model for providing the capability of acoustic transparency to audio watermarking and also exploit error correcting coding to facilitate the accuracy of the watermark extraction.
We embed the digital watermark in various genres of song in order to test the robustness of our technique. Simulation results demonstrate the robustness of the proposed hybrid audio watermarking technique, especially the resistance to the most popular MP3 attacks. The extracted watermark images are shown to prove the robustness of the proposed technique as well.
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Wu, Wen-Chih, and 吳文誌. "Audio Watermarking and Multiple-Sound-Source Localization Schemes." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/68142744379226898019.
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博士<br>國立中正大學<br>電機工程所<br>96<br>Audio watermarking using echo hiding has fairly good perceptual quality. However, security, robustness and imperceptibility are still relevant issues. This study presents the echo hiding scheme in which the analysis-by-synthesis, interlaced kernels, frequency hopping and variable-offset search are adopted to achieve high robustness, security and perceptual quality. The amplitudes of the embedded echoes are adequately adapted during the embedding process by considering not only the characteristics of the host signals, but also cases in which the watermarked audio signals have suffered various attacks. Additionally, the interlaced kernels are introduced such that echo positions of interlaced kernels for embedding “Zero” and “One” are inter-changed alternately to minimize the influence of host signals and various attacks on the watermarked data. Frequency hopping is employed to increase the robustness and security of the proposed echo hiding scheme in which each audio segment for watermarking is established by combining the fractions selected from all frequency bands based on a pseudo-noise sequence as a secret key. Finally, the variable-offset search scheme is employed to improve the robustness against pitch-scaling attacks. The cepstrum values at a reasonable range of echoes’ positions are investigated. The peak one of the cepstrum values in these positions is employed to determine the embedded watermark datum. Experimental results indicate that the proposed analysis-by-synthesis echo hiding scheme is superior to the conventional schemes in terms of robustness, security and perceptual quality.
On the other hand, the problem of multiple-sound-source localization is explored in this dissertation. Localization of multiple sound sources in a reverberant environment using a microphone array is a critical technique in video conference applications and is still a challenging task in audio signal processing. In this study, sound location involves multiple-sound-source separation, Time Delay Of Arrival (TDOA) calculation and spatial position determination. First, sound signals are estimated and separated from the mixtures received by a microphone array under a feedback architecture using the blind source separation algorithm. The TDOA parameters associated with microphones are calculated from the mixtures and then are used to estimate source signals by the time-domain cross correlation technique. Finally, the positions of sound sources are derived by the spatial position determination formulas. Experimental results demonstrate that the proposed multiple-sound-source localization scheme can effectively determine the locations of multiple sound sources in a near-field and reverberant environment.
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Fan, Jia-Rong, and 范家榮. "Digital Audio Watermark Based on Subspace Watermarking Method." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/19787993844423906428.
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碩士<br>國立交通大學<br>資訊工程系所<br>93<br>In recent years, due to the widespread use of Internet and great progress of the computer technologies, the proliferation of digital multimedia or documents is more and more important and can not be disregarded. To protect the intellectual property of the digital data, there has been significant interest in watermarking in recent days. We proposed a watermarking strategy from in which the watermark of a host audio data is selected from the robust features of the estimated forged audios of the host.
In this thesis, the robust features will be selected from the coefficients of the low frequency part of DCT coefficients after the DCT transformation. The forged audios are obtained from some software, such as LAME compression encoder and Stirmark Benchmark for Audio (SMBA). They perform potential pirate attacks on the host audio. We apply SVD technique on the features of the forged audios and obtain two orthogonal spaces. One of them characterizes most of the variations in the modifications of the host. We embed our watermark in the other space that most potential pirate attacks don’t touch. Thus, the embedded watermark is robust. According to the result of some experiments, it shows that our watermarking method can reach the goal of both of high detection probability and low false-alarm probability.
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Wu, Ming-Yan, and 吳明彥. "Audio Watermarking Method Based on Modified Patchwork Algorithm." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/78761253988284692229.
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碩士<br>國立交通大學<br>資訊科學系<br>91<br>Since computer science and network are developed, many data can be digitized and stored in hard discs or compact discs. Those data include text, image, audio, etc. This paper focuses on audio data, and presents a good audio watermarking method based on modified patchwork algorithm. It can satisfy our requirement when we need to hide information in audio data.
The kernel of proposed audio watermarking method is the modified patchwork algorithm. We used mathematical probability and statistics to analyze the proposed embedding function and found the significance of its parameters. This study assists us to detect the watermarks from audio data reasonably. From the experimental results, we know how to control the parameters inside the embedding function to gain more robust audio watermarks and keep high audio quality. Experimental results show that the proposed audio watermarks can be almost preserved after MP3 compression and common signal processing manipulations.
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Tsai, Roh-Wang, and 蔡若望. "Statistical Analysis of DCT Coefficients for Audio Watermarking." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/45802262042668775283.
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碩士<br>國立交通大學<br>電信工程系<br>91<br>In this thesis, we investigate an additive spread spectrum watermarking system in the discrete cosine transform (DCT) domain. The embedded watermark must be imperceptible by the user and should be robust to various signal manipulations. The detection problem can be formulated as a binary hypothesis test with the aim at maximizing the probability of detection conditioned to a given probability of false alarm. Furthermore, the decoding performance can be measured in terms of the probability of error. Most current research concentrate on correlation detectors, despite evidence showing that the underlying Gaussian model assumption does not match the intrinsic natures of DCT coefficients. Recognizing this, we will propose a statistical approach to model the DCT coefficients of the audio and then use it as a basis for the application of statistical decision theory to the design of efficient detection and decoding structures.
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Wei, Lee Jia, and 李家維. "Applied Digital Watermarking System on Digital Audio Signals." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/25402823015561461414.
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碩士<br>國立清華大學<br>資訊工程學系<br>91<br>In this thesis, we propose a digital watermarking scheme applied to digital audio signals to protect copyright. This watermark can be a 2D logo, a barcode image, or other information about the music. To satisfied two main features: inaudibility and robustness, we works on frequency domain. In this system, we do block DCT to original digital audio signal and embed watermarks into the coefficients. In order to get the embedded watermark in the correct position, we add a small signal in front of blocks for synchronization.
We test this scheme under common audio editing processing, like re—sampling, re—resolution, and MP3 compression. Experiments show that we can extract watermark correctly in most situations, especially in MP3 compression.
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Yu, Chih-Kai, and 游智凱. "Implementation and Improvement of Audio Watermarking Using MCLT." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/97589364408979690855.
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碩士<br>國立臺灣大學<br>資訊工程學研究所<br>104<br>Audio watermark is a technology used for DRM (Digital Rights Management) in earlier days. Now, with the increase of popularity and improvement of computation of smartphones and tablets, we can transmit information via audio watermark. The advantage of audio watermark is that it only requires a speaker and a microphone.
In this paper, we implement audio watermark system by using MCLT (Modulated Complex Lapped Transform), and embed data by modifying the phase of the MCLT coefficients because of the imperceptibility of human auditory to modified phase. As a result, we can hardly distinguish the transformed signal from the original audio signal. The MCLT does not produce blocking artifacts so we can get better audio quality.
Audio watermark is very sensitive to any acoustic interferences, and even the microphone’s directions will make impact on accuracy. There are two main problems in audio watermark using MCLT. First, some audio signal’s energy is too weak to extract data. Second, the coefficients of MCLT will rotate under some acoustic interferences, and this will lead to data extraction error. For the first problem, we mix the specific frequency band of white noise signal to the audio signal, and increase the energy of weak parts. For the second problem, we use K-means clustering as a solution, and we also try to alter the initial center of K-means clustering to improve the result.
In our experiments, the mixing of white noise signals, distances, angles, microphone’s directions, music genre and segment size are independent variables, and we tried many possible combinations to simulate the practical situations. We recorded many audio signals and decoded the result using the proposed system. As a result, we obtain a greater improvement of accuracy by adding white noise signal energy to the audio signal.
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Yong-SiangSyu and 徐詠翔. "Spread Spectrum Audio Watermarking Based on Complementary Codes." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/x2k96s.
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Krishna, Kumar S. "Blind Detection Techniques For Spread Spectrum Audio Watermarking." Thesis, 2007. https://etd.iisc.ac.in/handle/2005/588.
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In spreads pectrum (SS)watermarking of audio signals, since the watermark acts as an additive noise to the host audio signal, the most important challenge is to maintain perceptual transparency. Human perception is a very sensitive apparatus, yet can be exploited to hide some information, reliably. SS watermark embedding has been proposed, in which psycho-acoustically shaped pseudo-random sequences are embedded directly into the time domain audio signal. However, these watermarking schemes use informed detection, in which the original signal is assumed available to the watermark detector. Blind detection of psycho-acoustically shaped SS watermarking is not well addressed in the literature. The problem is still interesting, because, blind detection is more practical for audio signals and, psycho-acoustically shaped watermarks embedding offers the maximum possible watermark energy under requirements of perceptual transparency.
In this thesis we study the blind detection of psycho-acoustically shaped SS watermarks in time domain audio signals. We focus on a class of watermark sequences known as random phase watermarks, where the watermark magnitude spectrum is defined by the perceptual criteria and the randomness of the sequence lies in their phase spectrum. Blind watermark detectors, which do not have access to the original host signal, may seem handicapped, because an approximate watermark has to be re-derived from the watermarked signal. Since the comparison of blind detection with fully informed detection is unfair, a hypothetical detection scheme, denoted as semi-blind detection, is used as a reference benchmark. In semi-blind detection, the host signal as such is not available for detection, but it is assumed that sufficient information is available for deriving the exact watermark, which could be embedded in the given signal. Some reduction in performance is anticipated in blind detection over the semi-blind detection. Our experiments revealed that the statistical performance of the blind detector is better than that of the semi-blind detector. We analyze the watermark-to-host correlation (WHC) of random phase watermarks, and the results indicate that WHC is higher when a legitimate watermark is present in the audio signal, which leads to better detection performance. Based on these findings, we attempt to harness this increased correlation in order to further improve the performance. The analysis shows that uniformly distributed phase difference (between the host signal and the watermark) provides maximum advantage. This property is verified through experimentation over a variety of audio signals.
In the second part, the correlated nature of audio signals is identified as a potential threat to reliable blind watermark detection, and audio pre-whitening methods are suggested as a possible remedy. A direct deterministic whitening (DDW) scheme is derived, from the frequency domain analysis of the time domain correlation process. Our experimental studies reveal that, the Savitzky-Golay Whitening (SGW), which is otherwise inferior to DDW technique, performs better when the audio signal is predominantly low pass. The novelty of this work lies in exploiting the complementary nature of the two whitening techniques and combining them to obtain a hybrid whitening (HbW) scheme. In the hybrid scheme the DDW and SGW techniques are selectively applied, based on short time spectral characteristics of the audio signal. The hybrid scheme extends the reliability of watermark detection to a wider range of audio signals. We also discuss enhancements to the HbW technique for robustness to temporal offsets and filtering. Robustness of SS watermark blind detection, with hybrid whitening, is determined through a set of experiments and the results are presented. It is seen that the watermarking scheme is robust to common signal processing operations such as additive noise, filtering, lossy compression, etc.
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Krishna, Kumar S. "Blind Detection Techniques For Spread Spectrum Audio Watermarking." Thesis, 2007. http://hdl.handle.net/2005/588.
Full textAbstract:
In spreads pectrum (SS)watermarking of audio signals, since the watermark acts as an additive noise to the host audio signal, the most important challenge is to maintain perceptual transparency. Human perception is a very sensitive apparatus, yet can be exploited to hide some information, reliably. SS watermark embedding has been proposed, in which psycho-acoustically shaped pseudo-random sequences are embedded directly into the time domain audio signal. However, these watermarking schemes use informed detection, in which the original signal is assumed available to the watermark detector. Blind detection of psycho-acoustically shaped SS watermarking is not well addressed in the literature. The problem is still interesting, because, blind detection is more practical for audio signals and, psycho-acoustically shaped watermarks embedding offers the maximum possible watermark energy under requirements of perceptual transparency.
In this thesis we study the blind detection of psycho-acoustically shaped SS watermarks in time domain audio signals. We focus on a class of watermark sequences known as random phase watermarks, where the watermark magnitude spectrum is defined by the perceptual criteria and the randomness of the sequence lies in their phase spectrum. Blind watermark detectors, which do not have access to the original host signal, may seem handicapped, because an approximate watermark has to be re-derived from the watermarked signal. Since the comparison of blind detection with fully informed detection is unfair, a hypothetical detection scheme, denoted as semi-blind detection, is used as a reference benchmark. In semi-blind detection, the host signal as such is not available for detection, but it is assumed that sufficient information is available for deriving the exact watermark, which could be embedded in the given signal. Some reduction in performance is anticipated in blind detection over the semi-blind detection. Our experiments revealed that the statistical performance of the blind detector is better than that of the semi-blind detector. We analyze the watermark-to-host correlation (WHC) of random phase watermarks, and the results indicate that WHC is higher when a legitimate watermark is present in the audio signal, which leads to better detection performance. Based on these findings, we attempt to harness this increased correlation in order to further improve the performance. The analysis shows that uniformly distributed phase difference (between the host signal and the watermark) provides maximum advantage. This property is verified through experimentation over a variety of audio signals.
In the second part, the correlated nature of audio signals is identified as a potential threat to reliable blind watermark detection, and audio pre-whitening methods are suggested as a possible remedy. A direct deterministic whitening (DDW) scheme is derived, from the frequency domain analysis of the time domain correlation process. Our experimental studies reveal that, the Savitzky-Golay Whitening (SGW), which is otherwise inferior to DDW technique, performs better when the audio signal is predominantly low pass. The novelty of this work lies in exploiting the complementary nature of the two whitening techniques and combining them to obtain a hybrid whitening (HbW) scheme. In the hybrid scheme the DDW and SGW techniques are selectively applied, based on short time spectral characteristics of the audio signal. The hybrid scheme extends the reliability of watermark detection to a wider range of audio signals. We also discuss enhancements to the HbW technique for robustness to temporal offsets and filtering. Robustness of SS watermark blind detection, with hybrid whitening, is determined through a set of experiments and the results are presented. It is seen that the watermarking scheme is robust to common signal processing operations such as additive noise, filtering, lossy compression, etc.
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Jun-Horng, Chen. "Quantization-Based Digital Image Watermarking." 2005. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2106200511424700.
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Chin-Hao, Chang, and 張至豪. "Image Watermarking Using Lifting Scheme." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/04119386741789033713.
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碩士<br>國立成功大學<br>工程科學系<br>88<br>Due to the widely distribution of the Internet, it becomes very easy to obtain and distribute digital data. However, the protection of intellectual property comes up to be an important subject. For a digital data, there are many techniques to be used to provide the protection of intellectual property. To embed a special digital watermark into an original digital data is a popular and usually used technique. On the other hand, wavelet domain can provide both local and global properties. In this thesis, a quantization based watermarking scheme - Lifting scheme is employed to handle the wavelet transformation. The meaningful binary watermark is embedded into different resolutions of wavelet domain by using the quantization scheme. To present the robustness of proposed method, four attacks - JPEG compression, quantization, blur and crop are used to evaluate to proposed method. It is show that it does not need the original digital data to assistant the extraction of the watermark. The extracted watermark can also be recognized when JPEG compression rate is 26. Under properly allocation of the watermark it is also show that it can retain sufficiently watermark information.
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Zhuang, Fu-Kai, and 莊富凱. "New Image-Adaptive Watermarking Schemes." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/59190733430437598883.
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碩士<br>國立中正大學<br>資訊工程研究所<br>88<br>In this study, new image-adaptive watermarking schemes are proposed. Here the watermark is a binary gray-level signal with bipolar distribution or a pseudorandom gray-level signal with Gaussian distribution, which is designed for use in the block-wise DCT (discrete cosine transform) domain, i.e., the host image is partitioned into equal-sized non-overlapped blocks. Each block is transformed by DCT and the watermark is embedded into the host image by modifying the DCT coefficients. Instead of embedding the watermark into certain DCT coefficients (low, medium, or high frequencies), in this study the watermark is image-adaptively embedded into the host image, i.e., more watermark information is embedded into the larger DCT coefficients of complex blocks, and vice versa.
In the proposed schemes, to resolve the rightful ownership of an image, a one-way hash function is employed and the original (host) image is required so that the proposed schemes are non-invertible and each image owner has a private key. To improve the image quality of the watermarked image, the JND (just-noticeable distortion) concept of the human visual system (HVS) is employed in this study. JND expresses a critical distortion profile in the sense that if the distortion caused by the watermark is below the JND threshold at all points in time, space, or frequency, the distortion in the watermarked image is imperceptible by the human visual system (HVS). Using the original (host) image, as well as the difference of statistical properties, the means and the variances, of all the blocks within the original and watermarked images, the proposed schemes can recover the high-quality watermark from the watermarked image. Based on the experimental results obtained in this study, the performances of the proposed schemes are superior to that of some existing schemes for comparison.
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Chen, Jun-Horng, and 陳俊宏. "Quantization-Based Digital Image Watermarking." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/27388002432253866508.
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博士<br>國立臺灣大學<br>電機工程學研究所<br>93<br>The computer networks and mass storage devices make the exchange and spread of digital multimedia content more easy than before, yet challenge the copyright protection and obstruct the development of creative work. In addition, many fantastic software can tamper the digital content imperceptibly, and thus raise the difficulty of authentication. Consequently, watermarking techniques are extensively discussed with the aim to address these issues and provide the DRM (Digital Rights Management) with a firm basis.
This dissertation presents a preliminary discussion of watermarking systems. Each part of a generic watermarking scheme is discussed essentially. In the invisible watermarking systems, three important properties: transparency, robustness, and capacity, are typically evaluated to criticize the performance of a watermarking system. However, these properties are demanded different extents depending on what applications the watermarking systems are applied.
Many researches regarded the watermark as the message to be sent over a digital communications system, and the transmitting will inevitably sustain the interference from the host signal and the superimposed noise from attacks. However, this viewpoint ignores the fact that the host signal is known to the watermark embedder. The quantization-based watermarking has the inherent advantage that the host signal is taken into account for rejecting the interference from it, where the QIM (Quantization Index Modulation) is the representative approach. This study analyzes and compares a variety of improving skills for quantization-based watermarking. The experimental results have shown that those improving skills more or less accomplished their expectation in some restricted scenarios, but not for all the cases. In this dissertation, the non-centric quantization is proposed to improve the robustness of quantization-based watermarking. The simulation results have demonstrated that the proposed scheme outperforms the convectional quantization-based watermarking for most of the applicable cases.
This study also presents the watermarking schemes based on vector quantization (VQ), which inherently have the feature of joint watermarking and compression (JWC). A modified binary tree splitting method (BTSM) is proposed to generate the codebook for VQ, and the watermark message is thus embedded by the replacement of the representative index when the host vector is encoded. The performance superiority over other watermarking schemes based on VQ is presented. Notably, the lightness of computation cost of the proposed scheme enhances its applicability.
Most of the watermarking approaches are proposed for the host images in gray-level. As for the color host images, the most intuitive approach is directly applied the methods designed for gray-level images to the tri-channel signals of the host images. This study evaluates the performances of the watermark messages embedded into different channels of the color host image. The experimental results have shown that the answer to "which channel of the color host image is suitable for embedding watermark message?" is indecisive, yet should be answered according to the attack to which the watermarked images will resist. The color quantization based on the Fibonacci lattice has been proven to be competitive to other approaches for its good visual quality and the simplicity of color palette generation at decoder end. A novel image watermarking approach, Fibonacci Lattice Index Modulation (FLIM), is specifically proposed for the color image watermarking in this study. FLIM unobtrusively embeds a fragile watermark into the chromatic component for the purpose of authentication. With another robust watermark embedded into the luminance component by the QIM approach, the hybrid watermarking system embeds two watermark messages with different purposes concurrently, and can thus be applied to a variety of scenarios.
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Liao, Chi-Jen, and 廖吉仁. "Amplitude Attack-Based Image Watermarking." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/42241266089954874240.
Full textAbstract:
碩士<br>義守大學<br>資訊工程學系<br>92<br>Recently, with the rapid growing of internet networks, the use and transmission of digital media increase. However, it will cause the media being easily usurped by the unauthorized persons. The watermarking technology is one of popular methods for protecting the digital media's intelligence proprietary, which has received wide attention in the recent years.
In real applications, the watermark embedded in the host image will be attacked unintentionally or intentionally. How to survive from the attacks is a very important research issue. In this thesis, we analyze the unintentional attacks, especially degradation in amplitude, called amplitude attack (AA). Three types of amplitude attacks are obtained through detail analysis: Positive, Negative and Random. Based on the analysis, we design a new AA-based watermark technique, which includes three types of detection schemes corresponding to the above attacks. In addition, we study the preprocessing issue of a real watermark and present a watermark duplication scheme. Finally, combining the AA technique and duplication scheme, an image watermarking system with high robustness and reliability is developed.